Answer:
Example
0.5 mol of sodium hydroxide is dissolved in 2 dm3 of water. Calculate the concentration of the sodium hydroxide solution formed.
Concentration =
Concentration = 0.25 mol/dm3
Volume units
Volumes used in concentration calculations must be in dm3, not in cm3. It is useful to know that 1 dm3 = 1000 cm3. This means:
divide by 1000 to convert from cm3 to dm3
multiply by 1000 to convert from dm3 to cm3
For example, 250 cm3 is 0.25 dm3 (250 ÷ 1000). It is often easiest to convert from cm3 to dm3 before continuing with a concentration calculation.
Question
100 cm3 of dilute hydrochloric acid contains 0.02 mol of dissolved hydrogen chloride. Calculate the concentration of the acid in mol/dm3.
Reveal answer
Converting between units
The relative formula mass of the solute is used to convert between mol/dm3 and g/dm3:
to convert from mol/dm3 to g/dm3, multiply by the relative formula mass
to convert from g/dm3 to mol/dm3, divide by the relative formula mass
Remember: the molar mass is the Ar or Mr in grams per mol.
Example
Calculate the concentration of 0.1 mol/dm3 sodium hydroxide solution in g/dm3. (Mr of NaOH = 40)
Concentration = 0.1 × 40
= 4 g/dm3
Answer:
The magnesium atom loses 2 electron to the 2 atoms of chlorine. The 7 valency electrons of each chlorine atom will now be 8 to attain stable configuration. The final compound is written as MgCl2.
Explanation:
Ionic compounds are compound formed from the transfer of electron(s). One atom of the element loses electron(s) while the other atom gains electron(s).
The compound Magnesium chloride is an ionic compound . The bond between an atom of magnesium and 2 atoms of chlorine is an ionic bonding.
The valency electron of magnesium is 2 electron , for the atom of magnesium to attain octet rule, it will easily lose it 2 electrons to the chlorine atoms.
The chlorine atom on the other hand has 7 valency electrons, to attain octet configuration it will most likely gain 1 electron to become stable.
The magnesium atom loses 2 electron to the 2 atoms of chlorine. The 7 valency electrons of each chlorine atom will now be 8 to attain stable configuration. The final compound is written as MgCl2.
Answer:
ATOMIC number of element A is 3
Explanation:
Atomic number is the same as number of protons of an element.
according to the periodic table, Lithium is the element with 3 protons in its neutral state and it's atomic number is 3.
I believe the correct answer is option B. Molarity is the <span>number of moles of solute that is dissolved in 1 liter of solution. It is another way of expressing concentration of a mixture especially for solutions. Percent by mass is grams solute per grams of solution. Percent by volume is liter solute per liter per solution.</span>
